Molecular characterization of Clinical carbapenem-resistant Acinetobacter baumannii isolates from two tertiary care hospitals in Indonesia

Background: Carbapenem-resistant Acinetobacter baumannii (CRAB) is an important pathogenic bacterium that can cause nosocomial infection in hospitalized patients with various manifestations. The purposes of this recent study were to determine the prevalence, antimicrobial susceptibility profiles, carbapenemase-producing phenotypic and genotypic of CRAB in two tertiary care hospitals in Indonesia. Methods: A. baumannii isolates collected from patient’s clinical cultures in two tertiary care hospitals in Malang and Manado were included. Identifications of meropenem-resistant A. baumannii isolates with the vitek2® system results, followed by a sensitivity test using 10 µg imipenem antibiotic disc according to CLSI guidelines to fulfill the criteria as CRAB isolates. We assessed carbapenemase-production using mCIM and eCIM, and determined the presence of bla_KPC, bla_NDM, bla_OXA-23 carbapenemase resistance genes using simplex PCR. Results: 73 CRAB were collected from hospitalized patients, of which 30 CRAB from Manado and 43 CRAB from Malang. The largest number of samples came from sputum and indicates that XDR has also occurred in all CRAB isolates. Carbapenemase-production test using mCIM obtained positive results on 29 samples (96.7%) and 42 samples (97.7%) in Manado and Malang, respectively. The eCIM showed metallo-β-lactamase was dominant in two tertiary care hospitals. The prevalence of carbapenemase resistance genes was obtained bla_OXA-23 and bla_NDM ranged between 60%-90.7% and 3.3%-4.6%, respectively. bla_KPC gene was not detected. Conclusions: We showed that CRAB isolates positive result of carbapenemase-production and carbapenemase resistance genes of bla_OXA-23 seem to be dominant in two tertiary care hospitals in Malang and Manado, Indonesia. A national prevention and surveillance system should be prepared to reduce and limiting transmission of CRAB isolates.